Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

The function $f(x)=\left\{\begin{matrix} \frac{|x|}{x}, & if & x≠0\\0, & if & x=0\end{matrix}\right.$ is :

Options:

Continuous at x=0

Discontinuous at x=0

Continuous for all $x \in R$

Discontinuous for all $x \in R$

Correct Answer:

Discontinuous at x=0

Explanation:

$f(x)=\left\{\begin{matrix} \frac{|x|}{x}, &x≠0\\0, &x=0\end{matrix}\right.$

$f(x)=\left\{\begin{matrix}-1, &x<0\\0, &x=0\\1,&x>0\end{matrix}\right.$

so $LHL=-1(x=0),RHL=1(x=0)$

$f(0)=0$

discontinuous at $x=0$ $(f(0)≠LHL≠RHL)$